The major damage to bridges occurs during
floods. Damage is caused for various reasons, the main reason
being scour at bridge foundations, namely piers and abutments.
This book covers the description of, analysis of, and design for
scour at bridge foundations. The central focus is the combination
of old and new design methods into a comprehensive methodology
for bridge-scour design. The book is based upon an extensive summary
of existing research results and design experience, such material
not being previously adequately collated. The book serves as both
a handy reference text, and also a manual for the practicing bridge
designer.

Thirty-one detailed case studies of scour-induced bridge
failure are presented in Chapter 2 to provide designers with an
understanding of processes involved and also cases against which
design methodologies can be tested. The data and basic engineering
analyses required for bridge scour estimation are discussed in
Chapter 3. Detailed descriptions and procedures for estimation
of general scour, contraction scour and local scour are given
in Chapters 4, 5 and 6, respectively. A summary of the procedures
for total scour depth estimation is presented in Chapter 7 in
the form of an overall design method for scour analysis. Worked
examples are provided in Chapter 8 to illustrate application of
the proposed design methodology to a variety of situations, including
a number of the presented case studies. Chapter 9 presents principles
applicable to scour-resistant design, together with a comprehensive
summary of scour protection methods and remedial methods for bridge
scour. ISBN 1-887201-18-1. Publ. 1999 WRP.

Evaluating Scour at Bridges is the fifth edition of HEC-18. It presents the state of knowledge and practice for the design, evaluation and inspection of bridges for scour. There are two companion documents, HEC-20 entitled "Stream Stability at Highway Structures," and HEC-23 entitled "Bridge Scour and Stream Instability Countermeasures." These three documents contain updated material from previous editions and continued research by NCHRP, FHWA, State DOTs, and universities. This fifth edition of HEC-18 also contains revisions obtained from further scour-related developments and the use of the 2001 edition by the highway community. The major changes in the fifth edition of HEC-18 are: expanded discussion on the policy and regulatory basis for the FHWA Scour Program, including risk-based approaches for evaluations, developing Plans of Action (POAs) for scour critical bridges, and expanded discussion on countermeasure design philosophy (new vs. existing bridges). This fifth edition includes: a new section on contraction scour in cohesive materials, an updated abutment scour section, alternative abutment design approaches, alternative procedures for estimating pier scour, and new guidance on pier scour with debris loading. There is a new chapter on soils, rock and geotechnical considerations related to scour. Additional changes include: a new approach for pier scour in coarse material, new sections on pier scour in cohesive materials and pier scour in erodible rock, revised guidance for vertical contraction scour (pressure flow) conditions, guidance for predicting scour at bottomless culverts, deletion of the "General Scour" term, and revised discussion on scour at tidal bridges to reflect material now covered in HEC-25 (1st and 2nd Editions).

Title: Stream Stability at Highway Structures Fourth Edition
Description: This document provides guidelines for identifying stream instability problems at highway stream crossings. It is an update of the third edition published in 2001. The HEC-20 manual covers geomorphic and hydraulic factors that affect stream stability and provides a step-by-step analysis procedure for evaluation of stream stability problems. Stream channel classification, stream reconnaissance techniques, and rapid assessment methods for channel stability are covered in detail. Quantitative techniques for channel stability analysis, including degradation analysis, are provided, and channel restoration concepts are introduced. Significant new material in this edition includes chapters on sediment transport concepts and channel stability in gravel bed streams, as well as expanded coverage of channel restoration concepts. FHWA Publication Number: HIF-12-004

Title: Bridge Scour and Stream Instability Countermeasures Experience, Selection, and Design Guidance Third Edition, Volume 1
Description: Bridge Scour and Stream Instability Countermeasures: Experience, Selection, and Design Guidance, Hydraulic Engineering Circular No. 23 (HEC-23), identifies and provides design guidelines for bridge scour and stream instability countermeasures that are suggested for use by various State departments of transportation (DOTs) in the United States. Countermeasure experience, selection, and design guidance are consolidated from other FHWA publications in this document to support a comprehensive analysis of scour and stream instability problems and provide a range of solutions to those problems. Selected innovative countermeasure concepts and guidance derived from practice outside the United States are introduced. Management strategies for developing a Plan of Action (POA) for scour critical bridges are outlined, and guidance is provided for scour monitoring using portable and fixed instrumentation.
There are two companion documents, Evaluating Scour at Bridges (HEC-18) and Stream Stability at Highway Structures (HEC-20). These three documents contain updated material from previous editions. FHWA Publication Number: NHI-09-111

Title: Bridge Scour and Stream Instability Countermeasures Experience, Selection, and Design Guidance Third Edition, Volume 2
Description: Bridge Scour and Stream Instability Countermeasures: Experience, Selection, and Design Guidance, Hydraulic Engineering Circular No. 23 (HEC-23), identifies and provides design guidelines for bridge scour and stream instability countermeasures that are suggested for use by various State departments of transportation (DOTs) in the United States. Countermeasure experience, selection, and design guidance are consolidated from other FHWA publications in this document to support a comprehensive analysis of scour and stream instability problems and provide a range of solutions to those problems. Selected innovative countermeasure concepts and guidance derived from practice outside the United States are introduced. Management strategies for developing a Plan of Action (POA) for scour critical bridges are outlined, and guidance is provided for scour monitoring using portable and fixed instrumentation.
There are two companion documents, Evaluating Scour at Bridges (HEC-18) and Stream Stability at Highway Structures (HEC-20). These three documents contain updated material from previous editions. FHWA Publication Number: NHI-09-112